Tilting system

ABSTRACT

A relay or similar electromagnetic device in which an armature is tilted in response to the operating magnetic flux, and in which an orthogonal tilt freedom is provided to increase the ability of the relay to free sticking contacts, particularly in a double pole arrangement.

United States Patent 1191 Minks Sept. 17, 1974 [54] TILTING SYSTEM FOREIGN PATENTS OR APPLICATIONS lnvemorl Werner Minks, Kleingeschaidt 969,520 1958 Germany 335/128 Ger any 1,195,359 1965 Germany 335/128 [73] Assignee: International Standard Electric Corporation, New York, NY.

Filed: Oct. 31, 1973 Appl. No.: 411,369

Foreign Application Priority Data Oct. 31, 1973 Germany 2253456 References Cited UNITED STATES PATENTS 5/1969 Whitaker 335/128 Primary Examinerl-larold Broome Attorney, Agent, or FirmWillia'm T. ONeil [57] ABSTRACT A relay or similar electromagnetic device in which an armature is tilted in response to the operating mag netic flux, and in which an orthogonal tilt freedom is provided to increase the ability of the relay to free sticking contacts, particularly in a double pole arrangement.

6 Claims, 8 Drawing Figures 1 l 5c 1 5 n+1! l 1 i 36 I/ I 2 l 32 3| PAIENIEDSEPIYIW I -s'.aas'.s1a

with 0F 4 Y TILTING SYSTEM.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to electromagnetic/mechanical control, and more particularly to relays. g

2. Description of the Prior Art Devices of the type to which the present invention 1 relates are mostly used in miniature relay arrangements because, owing to the small field coils, particular care must be taken of the useful magnetic flux and any stray field, in order to obtain useful armature forces for the, switching.

An arrangement is known which employs an E-core, on the center core plate of which the coil is wound. The

into this portion of this L-shaped plate, the front plate of the armature in the operating position is parallel with the other end of the coil and core, both the leftand right-hand arms of the armature, in the operating posimagnetic circuit is completed-by a U-shaped armature whose front plate extends parallel with the plane of the coil front, and the two arms of which extend parallel in relation to the longitudinal coil axis. It is of advantage Other types of relay arrangements suffer from poor I fluxmanagement or inefficient space use or both, when their known techniques are applied tovery small relays.

, SUMMARY It may be said to have been the object of the present invention to provide an electromagnet/mechanical system for use in a relay, designed to afford a space-saving arrangement of the contacts. Moreover, the system has the object of enabling good magnetic flux management I so that there is afforded an increased pulling force if one of the contacts should happen to stick.

tion, are parallel with the coil axis, and the surfaces of the arms of the annature adjacent to the yoke are well set on the yoke. p

The preferred embodiment of the invention will hereinafter be described with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the entire electromagnetic/mechanical system of a relay according to the invention, in exploded viewform.

FIG. 2a shows the system of FIG. 1 in the operative position.

FIG. 2b shows the same system in the non-operative A posiiton.

FIG. 3a shows the armature in a non-tilted position.

FIG. 3bv shows the armature as tilted towards the right.

' FIG. 4a'shows a section taken through the front plate of the armatureas marked on FIG.4'b.

FIG. 4b shows a detail of the front plate of the armature.

' With respect to prior art devices of thetype described hereinbefore, this problem is solved in that the armature is supported so as to be capable of tilting .in

the plane'of its front plate. From the tilting movement of the armature within the plane of its front plate an advantageous result is the closing of a portion ofthe airgaps otherwise extant between the armature, the core and the yoke, in order to increase the magnetic fluxin the annatureThis is of particular advantage in cases where two. separate contact assembliesarranged next to the coil are actuated by means of the-two free ends of the arms of the pl'aneof its front plate an additional forcewhich acts upon the still sticking contact is thus produced.

Moreover, the givenproblem" is solved advantageously when the yoke is designed as an L-shaped plate, with the shorter portion ofthe plate extending parallel with a first end face of the coil. Accordingly then the core of the coil at that end is firmly anchored" v DESCRIPTION OF, THE PREFERRED EMBODIMENT Referring now-to FIG. 1, the magnetic circuit of the system will be seento consist of the L-shapedly bent yoke 2,'to the smaller surface of which there 'is to be firmly anchored, the coil I with its core end la. The I magnetic'circuit is completed by the U-shaped armature 3 whose front plate 31 extends parallel with the free coil face end 1b (and, core end 10). This is true when the two arms of the armature 32, 33 are arranged to be parallel with the longitudinal axisof the coil. The front plate, 31 of the armature has been extended (below .32 as viewed in FIG. 1) by a margin below both the left and the right arms (32 and 33 of the .an'nature. In this way the front'plate 31 of the annature will come to a'positionon-the surface of easing 6 in front (to the right on FIG. 1) of the yoke 2. It is advantageous for this extended portion of the front plate3l of thearrnatureto be in direct contact with the yoke 2 to enhance the magnetic flux between the yoke 2 and the armature 3, i.e., to decrease airgap reluctances in the magnetic circuit. As shown in FIG. 2a, the annature is seen, in its operative position, well set with'the surfacesof the armature anns 32 (and 33) seated on the yoke 2, and the frontpl'ate 31v of the armature is seated against the core end 1c of the-magnet (field) coil 1. The free ends of the armature arms 32 andj33 are provided with holes into which a rod (typically 36) is fitted. A linkage part 3.7 and another rod 38 provide a linkage assembly of ,a known type. As shown in FIG. 2a, the relay contact spring leaf 4 is deflected downward by this linkage, and contact is made between 5a and 5c.

' FIG. 2b shows the same system in the non-operative 1 position. The armature front plate 31 is tilted away from the end of yoke '2 and away from the core 1c or the coil.'-At the same time, there is formed a wedge shaped airgap between the edge surface of the arma- FIG. 3c shows the armature as tilted towards the left. I

ture arm 32, 33 facing the yoke 2, and the yoke 2 itself. The armature restoring force is produced by the contact (or springs) 4 engaging each of the two free ends of the armature arms 32 and 33 via the aforementioned linkage, to effect this lifting of the arm of the armature off the yoke 2.

Referring now to FIG. 3a, it will be recognized that the front plate 31 (end face of the armature) is uniquely designed. The bottom edges of 31, identified as 31a and 31b are chamfered by a relatively small amount so that the entire armature assembly 3 can rock or be tilted laterally as pictorially shown in FIGS. 3b and 3c.

It is assumed that the relay is a double-pole, doublethrow type, i.e., that there are two leaf and contact assemblies, i.e., two sets of parts 4 and 5a, b and one near the armature side am 32 and the other near 33, so that they are approximately equally spaced from the axial core center line on either side.

If it is assumed that one of the contacts a is stuck to the con'esponding 5b contact at the time of energization of coil 1, the armature will be constrained from assuming the fully magnetically seated position illustrated in FIG. 2a. Rather, one or the other chamfered edge 31a or 31b would tend to seat under magnetic action as in FIGS. 3b or 30, depending upon which contact pole was sticking.

The partial magnetic circuit closing thus effected tends to increase the activating force attempting to fully seat the armature 3, and accordingly tends to releasethe stuck contact. This increased magnetic force is extant between the core end and the armature plate 31.

In lieu of the two chamfered edges 31a and 31b, the same general type of tilting (rocking) effect of the armature can result if a punctual bearing point is provided for in the center of the side of the armature front plate 31 facing the yoke 2. this, of course, has the disadvantage that the magnetic flux between the armature 3 and the yoke 2 is deteriorated, because only a smaller portion of the front plate 31 of the armature is in direct contact with the yoke 2.

Another alternative within the scope of the present invention envolves the design of the longitudinal side of the front plate 31 of the armature facing the yoke 2 without slant-plane surfaces, but instead to provide a suitably profiled groove in the direct vicinity of the yoke armature facing side. This will offer the advantage of still further improving the magnetic flux between the yoke and the annature.

A further feature of the invention is shown in FIGS. 4a and 4b. A protrusion 35 is fabricated into the armature front plate 31 adjacent to the yoke 2. Thus, the surface 35a of this protrusion will be and in contact with the surface of the casing 6 when the armature 3 is fully seated. Thus the armature need not depend only on the narrow edge contact between 2 and 31 but rather will have mechanical support from casing 6, below.

For purposes of this disclosure, the word vertical center line, refers to a vertical line running upward through 35 up along the center of the armature end plate 31 (see FIG. 3a). Of course, this line might not ultimately be vertical in use unless the relay is physically oriented as illustrated.

What is claimed is:

1. An electromagnetically operated device for producing a mechanical movement in response to an electrical control signal, comprising:

first means including a coil and core for generating a magnetic flux in response to an electric current through said coil;

yoke means substantially in magnetic contact with a first end of said core and shaped to provide a flux path from said first end of said core to a position adjacent to the perimeter of said coil at the second end of said core;

second means including an armature having an end plate and two side plates forming a U-shaped, sheet metal part, the inside of said end plate engaging said core second end and the corresponding end of said yoke to close the magnetic circuit in operatron;

and means comprising a wedge shaped bottom portion on the part of said armature end plate adjacent said yoke, said wedge shape providing a high point measured in the plane of said annature end plate whereby said annature may assume a secondary tilt in a plane orthogonal to the plane of tilt produced by closure of said armature end plate against said core second end.

2. Apparatus according to claim 1 in which said wedge shape has a double slope and said high point is substantially at the vertical center line of said plate, whereby said armature secondary tilt may be in either sense in said orthogonal plane.

3. Apparatus according to claim 2 further defined in that said device is a relay having at least one set of electrical contacts side plates of said annature extend generally parallel to said coil and core and toward said first end of said core, and the open ends of said side plates are provided with mechanical linkages to operate said contacts.

4. Apparatus according to claim 3 in which said relay has two sets of contacts, the moving contact of each set being mechanically controlled through the one of said linkages on a corresponding armature side plate, whereby said armature secondary tilt will occur whenever a contact of either of said set of contacts sticks during operation, said flux path being enhanced on the side of said armature tilted toward said yoke to increase the mechanical force tending to break said stuck contact loose.

5. Apparatus according to claim 4 in which said yoke means is an L-shaped part of magnetic flux transmissive material, said yoke having a leg extending parallel to said coil and core axial centerline to a position oppposite said core second end.

6. Apparatus according to claim 4 in which a casing surface is provided to support said yoke leg in flat contact therewith, said armature end plate has an outward projection located at said high point, and said armature end plate bottom edge adjacent said yoke seats on said yoke leg at least partially, said projection providing support for said annature against said casing surface. 

1. An electromagnetically operated device for producing a mechanical movement in response to an electrical control signal, comprising: first means including a coil and core for generating a magnetic flux in response to an electric current through said coil; yoke means substantially in magnetic contact with a first end of said core and shaped to provide a flux path from said first end of said core to a position adjacent to the perimeter of said coil at the second end of said core; second means including an armature having an end plate and two side plates forming a U-shaped, sheet metal part, the inside of said end plate engaging said core second end and the corresponding end of said yoke to close the magnetic circuit in operation; and means comprising a wedge shaped bottom portion on the part of said armature end plate adjacent said yoke, said wedge shape providing a high point measured in the plane of said armature end plate whereby said armature may assume a secondary tilt in a plane orthogonal to the plane of tilt produced by closure of said armature end plate against said core second end.
 2. Apparatus according to claim 1 in which said wedge shape has a double slope and said high point is substantially at the vertical center line of said plate, whereby said armature secondary tilt may be in either sense in said orthogonal plane.
 3. Apparatus according to claim 2 further defined in that said device is a relay having at least one set of electrical contacts side plates of said armature extEnd generally parallel to said coil and core and toward said first end of said core, and the open ends of said side plates are provided with mechanical linkages to operate said contacts.
 4. Apparatus according to claim 3 in which said relay has two sets of contacts, the moving contact of each set being mechanically controlled through the one of said linkages on a corresponding armature side plate, whereby said armature secondary tilt will occur whenever a contact of either of said set of contacts sticks during operation, said flux path being enhanced on the side of said armature tilted toward said yoke to increase the mechanical force tending to break said stuck contact loose.
 5. Apparatus according to claim 4 in which said yoke means is an L-shaped part of magnetic flux transmissive material, said yoke having a leg extending parallel to said coil and core axial centerline to a position oppposite said core second end.
 6. Apparatus according to claim 4 in which a casing surface is provided to support said yoke leg in flat contact therewith, said armature end plate has an outward projection located at said high point, and said armature end plate bottom edge adjacent said yoke seats on said yoke leg at least partially, said projection providing support for said armature against said casing surface. 